The overall capacities of broadband satellites are increasing exponentially, and such capacity increases present unique challenges in the associated ground system and network designs. The goal of the system designers, system operators, and service providers is to support and provide efficient, robust, reliable and flexible services, in a shared bandwidth network environment, utilizing such high capacity satellite systems. For example, in a network with multiple remote nodes (e.g., remote terminals) using shared bandwidth to attempt to send data into the network, quality of service (QoS) is required on every link of the network in each direction. Further, an appropriate bandwidth allocation mechanism is required to achieve the QoS requirements for interactive traffic, while maintaining a balance to satisfy high throughput needs of remote terminals. In the satellite network, for example, supporting remote terminal data traffic requirements over the return or inroute link (the link from the remote terminal back to the gateway) presents significant challenges with regard to network resource management. Such challenges are due to various factors, including difficulty in balancing real-time data traffic requirements of each remote terminal versus aggregate bandwidth availability for all remote terminals.
Moreover, certain conditions may be present in such a system, such as: (1) the existence of interactive applications that are more latency sensitive such as VoIP and web-browsing, which require bursts of small bandwidth allocations when the application is actively transmitting data, (2) treatment of bulk traffic as lower priority, (3) receipt by remote terminals of bandwidth in anticipation of application requirements or for satisfaction of small bursty interaction needs, and (4) the fact that certain high throughput transfers are not long lived, and are thus benefited by a quick transfer time if network resources are available. In the presence of such conditions, it becomes a challenge to satisfy certain remote terminal bandwidth requirements. For example, such criteria may include utilization of request-based bandwidth allocation mechanisms to allocate bandwidth and meet the delay requirement for Interactive traffic, providing continuous dedicated bandwidth at some predefined rate that meets the delay requirement (which presents inefficiencies in terms of channel/bandwidth utilization), and addressing changes in application bandwidth requirements and continuing to allocate bandwidth in a manner that minimizes transmission delays and increases channel/bandwidth utilization.
Current bandwidth on demand (BOD) systems or algorithms (e.g., temporary priority inversion), however, fail to satisfy such criteria. In a shared bandwidth access network (e.g., a satellite network), while fairness can be proportionally achieved, a remote terminal may lose the chance to reach its subscribed rate plan, even for a short but sustained period of time. For example, on the shared return channel (the inroute from the remote terminal to the traffic gateway) of the satellite network, a backlog based Proportional Fair algorithm may be applied in bandwidth allocation among plural remote terminals. While fairness can be proportionally achieved, however, a terminal may lose the chance to reach its subscribed rate plan (e.g., even for a short but sustained period of time). Further, transmission of large data files cannot be accomplished at efficient speeds.
What is needed, therefore, is a system and method to address the challenges providing an appropriate bandwidth allocation mechanism in a shared bandwidth network environment, which assures subscribed throughput rates of a remote terminal for a sustained amount of time, facilitates satisfactory speed performance for remote terminals, and achieves efficient speeds for transmission of large data files, without affecting system performance.